Software Defined Networking – What’s in it for the customer?

While the terms Software Defined Networking (SDN) and Network Functions Virtualization (NFV) are often used in the same breath, they are complementary technologies offering greater promise when used together. NFV has to do with virtualizing switches and routers, while SDN separates the control plane and data plane of your network, leading to a programmable network which in turn facilitates easier deployment of business applications over that network. Rather than get bogged down into what the router/switch vendors are saying about SDN or NFV, let us step back and hear the perspective of the customer. What is motivating a telecom provider or an enterprise data center to consider SDN or NFV?

AT&T views NFV as a tool to reduce cycle time for rolling out new services and removing old services. AT&T seeks a common API (not necessarily an open API) between the SDN controller and the physical network devices. It recognizes that you can put some network software on Commercial off-the-shelf (COTS) devices but may end up retaining custom network hardware with proprietary ASICs to get the acceleration and higher throughput that COTS devices may not deliver.

Deutsche Telecom makes a fine distinction – They see in SDN a way to program “network services” (not network products) from a centralized location for a multi-vendor network partly located in-house and partly in the cloud.

If you ask the Hyperscale data centers like Facebook, Google, Rackspace they have a slightly different goal.

Facebook has a goal of gaining greater control of their networking hardware and taking away “secret ASIC commands” issued by router/switch vendors to equipment in the Facebook data center.

Google has as its goal a single view of the network, better utilization of network links and hit-less software upgrades.

A trading firm if asked for their expectations from SDN might say that they want to offer their customers big pipes with very low latency during trading hours and after-hours would like to pay less to their carrier for the same big pipe but with a higher latency to enable less latency sensitive applications like on-line backup.

The common thread here is services, the ability to roll-out services more effectively and create differentiation in a crowded price-sensitive market. In the follow-on articles we’ll look at what each of the major vendors has to offer and pros/cons of each SDN solution.